I’ve read that most people don’t get enough vitamin D. How much do we really need, and what are the best sources of vitamin D?

A 2009 study published in The Journal of the American Medical Association found that 75 percent of adolescents and adults in the United States have insufficient levels of “the sunshine vitamin” in their blood. Our bodies convert the sun’s ultraviolet rays to vitamin D, but because many of us work mostly indoors — and often apply sunscreen when we do spend prolonged time outside — our exposure to vitamin D-producing rays is low.

In 2010, the Institute of Medicine increased its official recommended daily dietary allowance for vitamin D from 200 international units (IU) to 600 IU. Some experts, however, think our daily intake should be much higher. The Vitamin D Council recommends 5,000 IU per day for adults — more than eight times higher than the official recommended daily allowance.

So why do we need this nutrient? Vitamin D is commonly associated with bone health because it helps the gut absorb calcium, which is the building block for strong bones. Vitamin D also activates genes that regulate the immune system, and a growing body of research suggests this important nutrient plays a role in the prevention of colon, prostate and breast cancers; high blood pressure; and diabetes. Seasonal Affective Disorder — which often strikes during winter, the darkest time of the year — has also been linked to low levels of vitamin D.

Most people are able to meet at least some of their vitamin D needs through exposure to sunlight. The amount of time needed in the sun varies greatly from person to person, and the variables include skin type, the amount of skin exposed, your age, the time of day and the season. Aim to find a balance between soaking up vitamin D-rich rays and protecting your skin from sun damage.

Stacked up against the sun’s rays, most foods aren’t rich sources of vitamin D — but mushrooms are an exception. When exposed to sunlight for a day or two (but no longer), their vitamin D levels soar from about 100 IU per 100 grams up to an incredible 46,000 IU per 100 grams! So, before you cook your mushrooms, give them their day in the sun. You can also take a cue from the mushroom experts at Fungi Perfecti and make a mushroom-based “sunshine” pill at home.

If you can’t spend time outside and don’t eat mushrooms, consider a vitamin D supplement. Two types of vitamin D supplements are available over the counter: D3 and D2. The D3 supplements are superior, because our bodies naturally produce D3 and are more receptive to absorbing and retaining it.

Hannah Kincaidis an Assistant Editor for MOTHER EARTH NEWS magazine. She is an enthusiastic student of herbal medicine, organic gardening and yoga. You can find Hannah on Google+.

I’ve heard that compost accelerators speed up composting and result in better compost. Are these claims true?

Most independent studies have concluded that those products aren’t worth the expense. The three types of commercially marketed compost “accelerators” and “activators” are based on microorganisms, nitrogen, or herbs prescribed for biodynamic composting, and you can easily add any of those substances to your compost without spending money on a store-bought product. Dead plants, weeds, kitchen scraps and the other biodegradable wastes that go into home compost introduce all the microorganisms needed for composting to proceed. If you like the idea of adding extra microbes to keep things moving swiftly, simply add a few shovelfuls of mature compost each time you start a new heap or batch.

When a gardener adds nitrogen to a lazy compost pile, the microbes take off, and their resulting population boom produces heat, which can help an almost-finished batch to finish faster. Free or cheap nitrogen sources, such as grass clippings, poultry manure or alfalfa meal, will push a slow heap into high gear as effectively as products sold as compost activators would—and will be much less expensive, to boot.

As for herbal additions, some gardeners grow comfrey or stinging nettle to feed to their compost as “activators.”

Contributing editorBarbara Pleasant gardens in southwest Virginia, where she grows vegetables, herbs, fruits, flowers and a few lucky chickens. Contact Barbara by visiting her website or finding her on Google+.

Why should I rotate my garden crops? If I do, what’s the best way to record what I’ve planted year after year?

Rotating your annual crops—even in a small-scale home garden—can help thwart potential gardening woes. If you plant the same crop in the same spot every year, overwintered pests, disease spores and nematodes can build up in that bed’s soil. A lack of rotation also means that the main nutrients a crop pulls from the soil will become depleted in that spot over time.

The first step to establishing successful rotation practices is to get to know the crop families. Plants should be rotated based on family, because crops in the same family generally have similar nutrient requirements, and they also attract many of the same pests and diseases. (You can print out a chart of common garden crops, grouped by family.)

A good rule of thumb is to avoid planting crops that are in the same family in the same spot in your garden more often than once every three to four years. If this is tricky because of limited space or the diversity of the crops you grow, don’t stress; it’s merely a good ideal to shoot for. Even a two-year rotation is better than nothing.

To start keeping simple crop-rotation records, draw out your garden beds on graph paper or in a gardening notebook or journal, and fill in what you’re planting where that season. You can use colored pencils to shade in planting areas based on which crop family is planted where — such as shading all tomato-family crops in red and all cabbage-family crops in green. Then, before you put any seeds or transplants in the ground the following season, sketch out a new planting arrangement for the year. Reference the previous year’s arrangement, and don’t put any related crops in the same location.

Another record-keeping option is to plan your garden with MOTHER EARTH NEWS’ Vegetable Garden Planner, which can track your crop rotation for you. When you draw out your garden beds on what is essentially digital graph paper, the Planner will automatically color-code your crops by family. Then, when you map out your planting arrangement the next year, the Planner will alert you if you’re planning to put a crop in a place where you recently planted a crop from within the same family. If you’d prefer to plan your plot on a mobile device, try the Grow Planner for iPhone or iPad.

Wetting one’s whistle can be difficult in winter! We asked our Facebook fans how to keep livestock water from freezing when the weather gets cold. Here are some of their super-cool techniques.

We always “bank” the tank with wet manure and cover it all with black plastic. We leave a hole for one-at-a-time drinking. The manure’s heat keeps the water from freezing too hard, even in our frigid Minnesota winters. — Barb Voth

We used to use electric water heaters. I have since built the solar stock tank from plans in MOTHER EARTH NEWS, which works amazingly, and I now save about $300 per month on electricity. (To read about the DIY solar stock tank Tina mentions, read Build a Solar Stock Tank. — MOTHER EARTH NEWS) Last winter here in the East was a true test, but we never had more than a skim of ice on the water in the morning thanks to our solar-heated unit. — Tina Durborow

My uncle built a motion-activated livestock waterer. When the cattle come for a drink, the motion sensor triggers the setup to pump water from way down in the ground. The water swirls around the bowl (which he made out of a tire), the cattle drink, and then the water drains back down. We live in Manitoba, where winter temperatures normally average minus 13 degrees Fahrenheit. — Carla Marsh

For our chickens, we set a regular incandescent light bulb inside a cinder block, put a metal water pan on top, and turn on the bulb (at least 60 watts). Presto! No ice. — Kate Hughes Brown

We use a submersible heater on a thermostat. When we get a week or two at minus 22 degrees, the heater will come on every hour. Our winter is seven months long, with temperatures mostly sitting at 15 to minus 6 degrees. Heaters make my life easier. — Andrea Procee

Most of my pastures have fresh spring water, but I have arranged mirrors in tandem to catch the midday sun and focus the sunlight on the water in our animals’ stock tank. — Joe Richardson

We mix molasses with warm water and then pour it into the water trough. The sugars in the molasses act as a natural antifreeze. The water will get slushy but typically won’t freeze, and the molasses encourages our horses to drink. — Peter Later

Can you recommend a reputable company or website that sells non-GMO, organic garden seeds?

So far, only a handful of common garden crops have been genetically engineered, and, as far as we know, no garden seed companies are knowingly selling genetically modified (GM) varieties at this time. Additionally, many garden seed companies sell Certified Organic seeds, and the certification rules prohibit genetic modification. Even if new GM varieties enter the market, as long as you choose Certified Organic garden seeds, you’ll be avoiding genetically modified organisms (GMOs).

Two mail-order companies that offer only Certified Organic seeds are High Mowing Organic Seeds and Seeds of Change. Certified Organic, GMO-free seeds are usually labeled as such in seed catalogs and on racks.

When choosing where to buy non-GMO seeds, you can also turn to companies that have signed the Safe Seed Pledge. This pledge is maintained by the Council for Responsible Genetics, and the companies that sign it promise not to knowingly sell GM seeds.

Unlike garden seeds, major farm crops — corn, soybeans, canola, sugar beets, alfalfa and cotton — are now predominantly GM, and 70 percent or more of foods in supermarkets directly or indirectly contain GMOs. For tips on how to forgo GM products in your everyday food purchases, read How to Avoid Genetically Modified Food.

Photo courtesy High Mowing Organic Seeds: All offerings from High Mowing Organic Seeds are Certified Organic.

Cheryl Long is the editor in chief of MOTHER EARTH NEWS magazine, and a leading advocate for more sustainable lifestyles. She leads a team of editors which produces high quality content that has resulted in MOTHER EARTH NEWS being rated as one of North America’s favorite magazines. Long lives on an 8-acre homestead near Topeka, Kan., powered in part by solar panels, where she manages a large organic garden and a small flock of heritage chickens. Prior to taking the helm at MOTHER EARTH NEWS, she was an editor at Organic Gardening magazine for 10 years.Connect with her onGoogle+.

I love butter made of cream from cows raised on pasture. I can’t find it in stores without spending a fortune, so I want to make it at home. Do I have to purchase a butter churn to do so?

You’re in luck: You don’t need a fancy butter churn or special equipment to make butter. You can easily produce 1 or 2 pounds with an electric blender, food processor or mixer. Some folks take the no-tech route and simply shake the cream in a glass jar until the butter separates. One quart of heavy cream will yield about 1 pound of butter.

If you want to make larger amounts of butter or like the idea of using an old-fashioned butter churn, you can find a nice selection of such implements online at Homesteader's Supply. Prices start at about $100 for a 1.7-quart hand-crank model and climb up to $8,650 for a 30-gallon electric churn.

Robin Mather is a senior associate editor at MOTHER EARTH NEWS and the author of The Feast Nearby, a collection of essays and recipes from her year of eating locally on $40 a week. In her spare time, she is a hand-spinner, knitter, weaver, homebrewer, cheese maker and avid cook who cures her own bacon. Find her on Twitter, Facebook or Google+.

I’m not sure what kind of production to expect from my hens annually. How many eggs can a chicken lay per year?

Your flock’s egg output will depend on many factors, including which breed you’re raising, the age of your hens, the quality of their feed, whether you provide supplemental lighting in winter, and how much protection you supply from extreme heat and cold.

If you choose an industrial hybrid breed and set your birds up in conditions that prompt intense production, each hen could lay as many as 300 eggs in her first year. Industrial birds are genetically programmed to lay so many eggs that they are spent after just two years, though, so most homesteaders don’t adopt this approach.

Home flocks tend to supply fewer eggs than chickens in an industrial setup. The staff at the Livestock Conservancy, a nonprofit dedicated to preserving heritage breeds, reports that egg generation in backyard flocks ranges from 120 to 250 eggs per hen annually. Some breeds lay far more eggs than others.

To maximize your flock’s production, you should remove older hens that are no longer laying or that are laying at a very reduced rate, and replace them with younger birds.

Originally, wild chickens laid eggs primarily in springtime for reproduction, but over centuries, humans have selected for birds that lay the most eggs year-round. Many breeds are still sensitive to day length and will naturally lay fewer eggs during the shorter days of winter.

Some people opt for artificial lighting to push their birds to continue laying through the colder months. If you allow your hens to rest in winter, they’ll likely live longer. Keep in mind that you’ll still be feeding them regardless of how much they’re laying, so your net annual cost per egg will be higher if you let the birds have a winter break.

Photo by Fotolia/vbaleha: Your decisions, as well as the age and breed of your birds, can affect your hens’ egg production.

Cheryl Long is the editor in chief of MOTHER EARTH NEWS magazine, and a leading advocate for more sustainable lifestyles. She leads a team of editors which produces high quality content that has resulted in MOTHER EARTH NEWS being rated as one of North America’s favorite magazines. Long lives on an 8-acre homestead near Topeka, Kan., powered in part by solar panels, where she manages a large organic garden and a small flock of heritage chickens. Prior to taking the helm at MOTHER EARTH NEWS, she was an editor at Organic Gardening magazine for 10 years.Connect with her onGoogle+.

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